Pelzmann



A. PELZMANN 2,732,621

ARTIFICIAL DENTURE AND METHOD OF MANUFACTURE Jan. 31, 1956 Filed April 15, 1954 INVENTOR. m

ARTIFICIAL DENTURE AND METHOD F MANUFACTURE 13 Claims. c1. 32-2 This invention relates to methods of making dentures containing magnets; to a novel device which facilitates practicing said method and makes it relatively quick and easy to properly position the magnets in said dentures; and to the improved dentures produced by said method.

Magnets are placed in dentures to react against each other and thereby to help push the dentures firmly against the adjoining gum ridges and palate. Magnetized dentures hithertofore have not been entirely satisfactory, because the magnetic reactive force is in large measure lost unless opposing poles in each pair of co-acting magnets are positioned as close to each other as possible. Furthermore, dental technicians have found the making of magnetized dentures to be unduly slow, tedious and cumbersome, and therefore expensive. Even so, magnetic dentures of the prior art have in the main been characterizd by insufiicient accuracy in the position of the co-acting magnets. The present invention eliminates all these difliculties.

Heretofore, in the construction of artificial teeth, both magnets and teeth were subject to much handling and alignment before the final denture was produced. With the maneuvering of the teeth to achieve proper occlusion and fit, and the conventional methods employed to produce the gum or base of the denture, there has been no assurance that the magnets would remain aligned. This invention consists of a simple and quick method of aligning the magnets, using a novel holder. The holder includes a rigid support which, once proper alignments are attained, assures that the magnets will retain their proper positions during the many steps involved in the manufacture of the dentures.

Accordingly it is an important object of the present invention to provide an improved method for making dentures containing magnets, whereby the magnets will be positioned in the final denture so as to have their maximum efiectiveness for the purposes intended.

Another important object is to provide a unitary positioning and anchoring device for such magnets which facilitates proper placement thereof, and which becomes an integral part of the finished denture.

Another object is to provide improved dentures possessing maximum magnetic repulsion, characterized by the accurate placement and retention of magnets therein.

Other objects will become evident from the following detailed description.

In the drawings:

Figure 1 is a perspective view of a magnet and the anchoring device;

Figure 2 is another embodiment of a positioning and retaining device, the position of the magnet therein being shown in broken lines;

Figure 3 is a perspective side view of a set of dentures, showing the invention;

Figure 4 is a view looking up towards the palatal portion of the upper denture;

Figure 5 is a cross-sectional view of an artificial tooth before insertion of the magnet;

2,732,621 Patented Jan. 31, 1956 Figure 6 is an exploded view of a tooth, magnet, and anchoring device;

Figure 7 is a cross-sectional view of the elements of Figure 6 in a flask and invested;

Figure 8 is a cross-sectional view of the final denture; and

Figure 9 is a cross-sectional view of a modified form of Figure 8.

Referring to Figures 3 and 4, there is shown a set of dentures comprising an upper denture 15 and a lower denture 16. The artificial teeth are of the usual types and may be of porcelain or other material customarily used for such purpose, and are attached to plastic or vulcanized rubber bases 17 and 18 of the dentures in the usual manner. These bases are colored to resemble the gums. Four permanent magnets 19 are embodied within the posterior teeth 20 and 21, and are arranged in pairs at each side of the dentures in such manner as to have similar magnetic poles disposed adjacent each other. The resulting magnetic force produced will cause a repelling action, thus acting to seat the dentures more firmly to the gums. Care must be taken to see that the magnets in each denture are properly placed with respect to the rest of the denture, and especially with respect to the cooperating magnet in the corresponding opposite denture. Since the tongue and mouth are very sensitive tactilely, this accuracy is needed to get proper reaction between the magnets and to give the wearer of the denture a comfortable fit. A poor alignment might cause loss of suction, dislodgment of the dentures, or slippage. Furthermore, the magnets must be precisely matched so as to have opposing poles as closely aligned as possible, or a large proportion of the magnetic repelling force will be lost. 1

It is preferable to seat the anterior magnetic pole within the mesial portion of the first bicuspid and extend the magnet posteriorly, having the posterior magnetic pole within the distal portion of the second molar. This permits using magnets having lengths several times their cross-sectional dimensions, and achieving a high magnetic efficiency.

Embedded within the teeth and extending around-a portion of the magnet is a tubular body portion 23 of the anchor device or magnet-holder, indicated generally at 22. The inner cross-sectional perimeter of body portion 23 is shaped to conform to the cross-section of the magnet which may be of any geometrical figure. Figure 1 shows a holder attached to a cylindrical magnet, and Figure 2 shows a holder around a magnet (shown in con ventional dot and dash lines) having a rectangular crosssection; The invention, however, is not limited to holders formagnets of these shapes. It is adaptable to magnets of any shape, such as C-shaped and L-shaped magnets, as well as being adaptable to various shaped cross-sections. The bore 23:: of tubular body portion 23 is a trifle smaller than the diameter of the magnet 19. To place body portion 23 around the magnet, magnet-holder 22 is heated to expand body portion 23 and magnet 19 is forced into the tubular opening. This gives a very tight fit. I

Extending from the body portion 23 is a supporting section 24. Since nylon has a smooth surface and would tend to slip, a heel or anchor portion 25 extends from the other end of support section 24. The anchor portion 25 is shaped to follow the contour of the longitudinal axis of magnet 19; hence acting as a parallel projection of the magnet. This allows a quick and accurate estimation ofthe positioniof a magnet embedded in the teeth. Anchor 25 also gives convenience to the handling and maneuvering of the holder and magnet.

Bearing surfaces 27 and 28 are provided in support section 24, and bearing surfaces 29 and 30 are provided on the anchor portion 30. The planes of upper surfaces 27 and 29 and lower surfaces 23 and 30 coincide in order I ment or by measuring with calipers or straight edge, the

to present two continuous bearing surfaces and facilitate the production of a unitary structure. To give strength and rigidity to the magnet-holder, fillet 26 is provided at the junction of body 23 and support 24. Also, it should be noted that sufiicient thickness and width are given to support 24 and anchor to prevent any bending or twisting by them, assuring that the magnets will remain stationary during the formation of the dentures.

Support section 24 is directed lingually when inserted in the denture. Thus, the location where it is cut or ground off will not be readily apparent when the dentures are in finished form. Further, section 24 is less wide than the length of anchor portion 25 so that it is not necessary to grind away much of the posterior facing 32 of the tooth or teeth through which section 24 will project. This allows a minimum marring of the surfaces of the teeth.

In selecting the material used in forming the magnetholder 22, it has been found desirable to avoid material that would be affected by either plaster, wax, or the plustic of the denture when in liquid form. Metal is undesirable since it affects the magnetic flux, would add unnecessary weight to the denture, and might produce toxication if exposed. Further, there is also the chance of exposing the mouth to sharp projections if part of t e facing of the tooth is broken away. The material chosen also should be able to retain its rigidity at temperatures to which the dentures would be exposed during manufacture and use, be inert to the chemical and physical conditions dentures are subjected to, and further be easily colored so that it will readily blend with the tooth and gum areas. Any of the materials possessing these qualities, such as plastics, may be picked by anyone skilled in the art. In the preferred embodiment of my device I use nylon. Furthermore, nylon material can be readily worked in forming the unitary molded magnet-holder 22.

In constructing the dentures, any of the known techniques for producing a plaster model 14 of the gums of the wearer may be employed. The upper and lower denture models are then oriented in an articulator (not shown) and their proper bite relationship determined. A wax bite or covering 31 is then placed over the models and the artificial teeth placed thereon in proper position, as shown in Figure 5. The lower posterior teeth 21a, 21b, 21c, 21d are then removed from the wax 31. Magnets .19, held by magnet-holders 22, are placed parallel to the upper plane of occlusion and on the wax covering 31, and sufficient wax is placed about the magnet-holders to hold them in fixed position. cover only a small portion of support 24, leaving its outer end and anchor 25 exposed at this time. Later, the exposed parts are invested with plaster and act to retain the magnets in position when cover 31 is removed.

Prior to the placing of the magnets 19 on the wax, the magnet-holders 22 are fitted to the magnets, first passing the holders through a flame and then pressing in the magnets. After the magnets and holders are in Care must be taken to place, the lower posterior teeth 21a, 21b, 21c, 21d, are 1 ground down to fit over the magnets 19 and holders 22 while in occlusion with the upper posterior teeth 20a, 29/2, 20c,, 20d.

The lower posterior teeth are again removed, as are the upper posterior teeth; and magnets 19, held by magnet-holders 22, next are seated parallel to the lower denture magnets. A small amount of wax is applied around the holders to hold them fixed, also, again leaving anchor 25 and part of support 24 exposed. It is, of course, desirable to set the magnets as close to the plane of occlusion as is possible without making the occlusal surfaces 33 of the teeth too thin. The maximum preferable distance between the magnets for eificient operation should be not more than 4 millimeters, however. This distance may be easily ascertained by use of calipers. After the magnets are set parallel, either by visual align I lower posterior teeth 21a, 21b, 21c, 21d, are again seated in place and the upper posterior teeth 20a, 20b, 20c, 20d, are ground down to fit over the upper denture magnets and holders when dentures 15 and 16 are in occlusion.

To form the finished denture the upper and lower plaster castings 14, teeth, magnets 19 and maget-holders 22 are placed in a flask 34 and invested with plaster 35. The flask and its contents are allowed to stand until the plaster 35 has set, and then they are placed in boiling water. This liquifies the Wax covering 31 which is removed when flask 34 is opened. The artificial teeth are retained by the plaster mold 35. Since anchor 25 and the outer portion of support 24 are invested with plaster, both magnets 19 and magnet-holders 22 are held firmly in place. Thus, there is no danger of magnets 19 being moved from their properly aligned positions. This is clearly indicated by Figure 7.

The upper and lower denture bases 17 and 18 are formed in a conventional manner. For example, an acrylic resin powder and a monomer liquid are mixed to form a dough-like substance which is then placed in the space formerly occupied by the wax 31. This substance is then subjected to the conventional packing process. Air bubbles and excess space produced in the teeth ground to embody the magnets 19, both of which would tend to weaken the dentures, will be filled during this process. Moreover, this assures that the magnets 19 will be fitted tightly into the final dentures. The dough is then cured until it sets hard.

After the dough has set, the flask is opened and the plaster broken away from the dentures. Any excess of the magnet-holder 22, such as shown at 36 in Figure 4, is cut or ground away. The denture is finished and polished, as shown in Figure 8.

It may be desired to countersink the nylon endof supporting section 24, as indicated at 37 in Figure 9, and cover it over with Lucite or a plastic solution 38 which would match the posterior facing of the teeth. Further, this would be particularly advisable when the wearer of the denture is allergic to nylon, or when constant and close contact by the mouth and nylon would produce allergy symptoms in those having allergic tendencies.

To facilitate the making of the dentures, the posterior teeth may be ground in advance in preparation for accom modating the magnets and holders to be placed therein.

The invention is not limited to the specific details of the method and device described above. Since both may be described in a variety of expressions, it is to be understood that the embodiment and method herein described are for the purpose of illustration only, and not intended to limit and define the invention. For example, the improved method and device for carrying it out are readily adaptable to instances where separate magnets are placed in each artificial tooth.

What is claimed is:

1. A device for positioning and retaining magnets in artificial dentures, including an integral molded nylon unit having a tubular body section having an inner crosssectional perimeter adapted to fit tightly about the outer perimeter of the magnet to prevent relative movement therebetwcen, a section supporting portion extending from the body section and connected at one end thereto, and an anchor section disposed parallel to the body section and connected to the outer end of said supporting portion, said supporting portion and anchor section having relatively wide and rigid upper and lower bearing surfaces, whereby the force applied to said bearing surfaces by plaster forms during the construction of the denture will prevent movement of the integral nylon unit and hence of the magnet.

2. A holder for magnets used in artificial dentures comprising an integral molded unit, including a hollow body portion adapted to fit tightly about a magnet, and a support section extending angularly from said body portion, said support section having bearing surfaces adapted to abut molds during manufacture of the denture.

3. A device for positioning and retaining a magnet in artificial dentures comprising an anchor means, means for receiving the magnet, and means extending angular- 1y to the axis of the magnet, connected with the magnet receiving means at one end, and connected at the other end to said anchor means.

4. The device as described in claim 3 in which the means for receiving the magnet includes a portion adapted to grip and firmly hold said magnet.

5. The device as described in claim 4 in which the portion adapted to grip and hold said magnet is of tubular cross-section and adapted to fit tightly about the outer perimeter of said magnet.

6. In an artificial denture, the combination including a denture base, a plurality of teeth joined to the base, a magnet embedded in and extending through said teeth, and an integral magnet anchor, said anchor having a portion connected to the magnet and a support extending out wardly therefrom to provide a seating means for the anchor and magnet.

7. The combination as described in claim 6 in which the portion of the anchor connected to the magnet is adapted to fit tightly about the outer perimeter of the magnet.

8. The combination, in an artificial denture including a denture base and a plurality of teeth joined thereto, of a permanent magnet and a magnet anchor means including a magnet holding portion, a substantially L-shaped extension, one leg of the extension being connected with the magnet holding portion and extending at an angle to the longitudinal axis of said magnet, the other leg of the extension being positioned in a plane parallel to the longitudinal axis of said magnet, whereby the position of the magnet and anchor may be ascertained when they are embedded in said teeth.

9. In the process of manufacturing artificial dentures containing magnets by producing plaster models, setting the teeth in correct alignment in temporary model coverings, and embedding magnets in the teeth before a final denture base is substituted for the covering, the improvement which comprises removing a plurality of lower posterior teeth and mounting magnets and anchor means in the lower jaw plaster model, said anchor means having a tubular body portion about the perimeter of said magnets and supporting sections extending therefrom, securing the anchor means and supporting sections to said model, fitting the lower posterior teeth over the magnets and in correct occlusion, removing said lower posterior teeth and a plurality of upper posterior teeth while leaving the lower denture magnets mounted, seating a second set of magnets and anchor means to the upper jaw model and in the desired alignment with said lower denture magnets, securing the anchor means and supporting sections of the second set of magnets to the upper jaw model, resetting said plurality of lower posterior teeth, fitting said upper posterior teeth over the magnets and in correct occlusion, investing the models, teeth and magnet anchors, removing said temporary coverings, said teeth being held in place by said plaster and said magnets being held by said anchor means embedded in said plaster, forming the upper and lower denture bases, packing and curing, and thereafter removing the dentures from said plaster and removing the excess of said anchor means.

10. The process as described in claim 9 wherein said anchor means body portions are placed about said magnets by expanding said body portions and press fitting said magnets therein.

11. In the process of manufacturing artificial dentures containing magnets, the improvement which comprises fitting said magnets with unitary magnet holders having support sections, embedding said magnets in teeth of said dentures, allowing a portion of said supports to be embedded with said magnets, securing said support sections and magnets in proper alignment by investing, processing the dentures, and removing that portion of said supports protruding from said teeth.

12. In the process of manufacturing artificial dentures containing magnets, the improvement comprising fitting anchor means having support and heel sections to said magnets, positioning said magnets and anchor means in a denture model, securing said magnets and a portion of said support sections to said model, embedding said magnets in teeth in said model, investing said teeth and anchor means in plaster, removing the temporary gum base on said model, applying a plastic to form a permanent denture base, and packing and curing.

13. The improved process as disclosed in claim 12 and including removing the denture from said plaster, and removing the excess of said anchor means protruding from said teeth.

Goldsmith Nov. 4, 1952 Feibelman Dec. 30, 1952 

